The subject matter disclosed herein relates generally to cryogenically cooled magnetic resonance imaging (MRI) systems, and more particularly to systems and methods for removing heat from heat sinks of the MRI systems.
In superconducting coil MRI systems, the coils forming the superconducting magnets are cryogenically cooled using a helium vessel. The cryogen cooling system of some of these MRI systems include a coldhead within a coldhead sleeve that operates to recondense vaporized cryogen to continually cool the superconducting magnet coils during system operation.
When the coldhead is off, for example, during transportation of the MRI system, power off of the MRI system during normal operation, or coldhead failure, the coldhead sleeve is heated due to contact between the coldhead and the coldhead sleeve. During this time, the coldhead sleeve acts like a heat sink (or heat source) and applies heat to the MRI system, including to a thermal shield and the helium vessel of the MRI system. In this condition with the coldhead sleeve acting like a heat sink and heating up the thermal shield and helium vessel, helium inside the helium vessel boils off. Thus, helium from the helium vessel is lost and must be replaced, which results in added cost and system maintenance.